sandsk8erz400

iTrader: (1)

I bought the car with the the exhaust the way it is. The muffler was cutout and they just ran pipe and a dual tip that looks like the CME tip. I like they way it sounds, I'm just wondering if it's hindering my gas mileage? I've seen the threads where guys say that they lose low end with no muffler, but I haven't found anything about the gas mileage.

my only other mod is a cai and I can only manage to get 13 mpg at most with city driving shifting before 2k. Freeway I get 26-28 so that seems about normal, but I'd like to get a little better in the city

So is not having a muffler decreasing my gas mileage?

JD_AMG

Doubt it. What grade gas are you using?
Also some stations have "up to 10% ethanol" posted up on their pumps as well and that will decrease your gas mileage too.

sandsk8erz400

iTrader: (1)

Chevron Premium, I plan on doing a small tune-up soon; new plugs, wires, etc. Maybe that will help out.

Texas 02 Z28

iTrader: (14)

Seafoam helped my MPG, fwiw. You should add it to your list of tune ups.
https://ls1tech.com/forums/general-m...-your-car.html


I personally don't think the lack of muffler would hurt your gas mileage. A tune should help a lot, maybe you're running crazy rich for some reason? I know when I had a pinched 02 sensor wire, I was running in open loop (limp mode), so the car ran stupid fat and I got horrible mpg's.

A tune should let you know if something's not right.

blk/slvr02ss

iTrader: (21)

The LM-1 has no muffler and a lot of people run that exhaust w/ out bad gas mileage.

01ssreda4

iTrader: (96)

i agree....

araber89

iTrader: (3)

Ok I have LT headers ORY and a LM. I still get 21 MPG just driving around and thats with seeing 5000RPMs three or four times a tank.

Sunset'01Z

iTrader: (10)

muffler should have little effect on gas mileage.. that's mostly changed by your right foot

sandsk8erz400

iTrader: (1)

I'll try the seafoam when I do the tune up. I just passed 80k so it's not like the car has a lot of miles. And even with a light foot the best i can manage in town is what I stated above. I do plan on doing a full exhaust (lt, maybe true duals) and I'll have it tuned then and see if that helps.

I do have probably a good 200lbs of stereo stuff in the car, think that could do it? I wouldn't quite think so since it'd be just like having a heavy passenger but maybe with the city driving it's enough to make a difference since I can still manage high 20's on the freeway.

COR6s

iTrader: (1)

if you are getting good MPG on the highway and crap in town its all in the tune im willing to bet if you get it tuned by hp tuners or EFI live by a good tuner it will squeeze 20-30 hp and about 20mpg city 28 hwy no problem

sandsk8erz400

iTrader: (1)

so even the stock tune could be the reason I am getting bad gas mileage?
& i also know that the blend for winter gas can cause a decrease in gas mileage but this has been going on since I started checking the gas mileage before last summer so it's not the winter blend.

Z28LS1camaroguy

iTrader: (3)

do the basics, plugs, air filter, seafoam helps a lot. do that stuff first and see if it helps then move on to tune and stuff like that.

1SLwLS1

iTrader: (6)

Stop and go traffic will hinder the "green"est of cars. Do you drive in traffic alot? Also driving under 2K can put a lot of load on the engine relative to the throttle position.

Blackhawk777

Damn.... I see about 20 with WAAAAAY more than a few 5000 rpm runs a tank. Hell I do that many in the first quarter when it's nice. Then again, I have a crappy *** handheld tune, and 3.73s with the lm so who knows.

sandsk8erz400

iTrader: (1)

Not really traffic, but there's a lot of stop signs and lights in my town so i'm constantly starting and stopping. And with the load on the engine relative to the throttle position, I think I understand what you mean. But all I do is take of and just lightly press the pedal enough to accelerate and shift when it comes to 2k. That isn't putting a load on it is it? I don't lug the motor, atleast I don't think.

1SLwLS1

iTrader: (6)

The stop and go is what is killing you. When your stopped, your still burning fuel not racking up miles, burning roughly .5-.8 GPH while moving a distance of 0. When you accelerate, your getting roughly 4 MPG at low speeds. The load thing isnt really relative, just that some people will mash the gas at low rpms in low gear(4th, 5th, 6th) and that will put a high load.

sandsk8erz400

iTrader: (1)

Yeah, that's kind of what I figured. I basically slowly accelerate and get into 4th gear and only hold it for a couple seconds before the next stop light or stop sign. So that, plus the extra couple hundred pounds of stereo equipment is probably whats doing it. I'll still do the tune up and seafoam, and a tune down the road when i do my full exhaust. Maybe that'll help out some.

Thanks for the help guys.